This paper describes a record of air and soil temperature collected from 2001 to 2016 in temperate forests at the Bear Brook Watershed in Maine (BBWM). BBWM is a long-term research site established to study the response of forest ecosystem function to various environmental disturbances, including chronic acidic deposition. Replicate HOBO data loggers were deployed in BBWM's two forest types (coniferous and deciduous), to record temperatures at four positions: (1) air temperature, 100 cm above the forest floor; (2) surface organic soil, 2 cm below the forest floor surface; (3) mineral soil, 10 cm below the organic-mineral horizon interface; and (4) mineral soil, 25 cm below the organic-mineral horizon interface. Data were recorded every three hours, and these raw data were used to compute daily maximum, daily minimum, daily average, and monthly average values. This fifteen-year record represents one of the few readily-available soil temperature datasets in the region, and provides information on long-term changes in climatology, and seasonal and episodic weather patterns.